A previous study by Gill and colleagues has shown that hospital admission in older people is associated with worsening functional ability. In order to clarify whether hospital admissions have a comparable effect on trajectories of disability at the end of life, the authors analyzed data from a longitudinal study that includes monthly assessments of hospital admissions and disability in essential activities of daily living in a large cohort of community-dwelling older people in the United States.

A total of 522 study participants who died within a 15-year period were included in the analytic sample, and trajectory modeling was used to identify the trajectories of disability. In the last year of life, six distinct trajectories of disability were identified, from least disabled to most disabled: 95 subjects (17.2%) had no disability, 61 (11.1%) had catastrophic disability, 53 (9.6%) had accelerated disability, 61 (11.1%) had progressively mild disability, 127 (23.0%) had progressively severe disability, and 155 (28.1%) had persistently severe disability.

During the study period, 392 (71.0%) participants had at least one hospital admission and 248 (44.9%) had multiple hospital admissions. For each trajectory, the course of disability closely tracked the monthly prevalence of hospital admission. Multivariable model analysis found that hospital admission in a given month had a strong independent effect on the severity of disability, in both relative and absolute terms. The largest absolute effect was observed for catastrophic disability, with a mean increase in disability score of 1.9 (95% confidence interval 1.5 to 2.4) in the setting of a hospital admission, corresponding to a rate ratio (or relative effect) of 2.0 (95% confidence interval 1.5 to 2.7).

Although the reported associations cannot be construed as causal relations, these results indicate that aggressive efforts should be made to minimize the adverse functional consequences of acute hospital admissions and enhance differentiated interventions for disability.